This research program is an integrated multidisciplinary project designed to relate structural and antigenic determinants of selected sexually transmitted pathogens to the clinical and epidemiological features of the disease they produce and the development of protective immunity. Two projects focus on the relationship between structural determinants in the gonococcus and their ability to elicit an immunological response. One concentrates on peptidoglycan and its role as an immunomodulating agent. The other focuses on structural aspects of outer membrane proteins and their role in the interaction of the gonococcus with host defense systems. Special emphasis is placed on a 76,000 dalton protein which appears to contain antigenic determinants common among all gonococci. Three projects address questions on the pathobiology of Chlamydia trachomatis. One proposes to further define its role in female infertility with special reference to the role of cervical factor and subclinical tubal infections. A second proposes to define the epidemiology, and relative roles of antigen specific humoral and cellular immunity in protection against relapse and reinfection. A necessary prerequisite for this project is the development of an immunotyping system based on type-specific monoclonal antibodies. Its ultimate goal is identification of those antigens which induce protective immunity in humans. The third chlamydial project proposes to characterize the structural interrelationships of the major components of the chlamydia outer membrane with the long term objectives of providing a model which can be used in further studies of pathogenesis. Two related projects concentrate on venereal warts and the human papilloma viruses responsible. One proposes to define the basic clinical epidemiology of venereal warts as well as their relationship to premalignant cutaneous lesions and their ability to induce serum antibody against common antigenic determinants. The other proposes to use cloned viral DNA from wart tissue, propagate it in tissue culture, and define viral transcripts and gene products. Assuming these objectives can be accomplished, viral proteins would be available which could be used to develop immunologic tests. These tests would be performed in conjunction with the clinical project to provide additional epidemiological data.